1. Field of Invention
The present invention relates to a multicarrier mobile communication system, particularly a method of scheduling bandwidth resource in the multicarrier mobile communication system.
2. Description of Prior Art
As a requirement for wideband service is increasing and multicarrier techniques (such as Orthogonal Frequency Division Multiplexing (OFDM) etc.) have been grown up, how to build up a new generation wireless cellular network becomes a problem to be solved.
For example, a current three-sector structure is a better scheme. However, since non-uniformity of a user distribution and a service distribution in the space would cause excessive bandwidth resource in some sectors and short of bandwidth resource in some other sectors, there is a need for flexibly scheduling the bandwidth resource among sectors in order to improve frequency spectrum utilization of the system.
Currently, the methods for improving the frequency spectrum utilization are as follows:    Static Channel Allocation: this method allocates a fixed bandwidth resource to each cell or sector. It is simple but can't well resolve the status of the non-uniformity of a user distribution and a service distribution;    Dynamic Channel Allocation: this method takes channels condition and inferences among cells into account, in order to allocate channel to respective cells in a centered or distributed way. The algorithm of the method is complex;    Mixed Channel Allocation: this method divides the bandwidth resource into two parts, one for static bandwidth resource which may only be used by its own cell and sector and the other for dynamic bandwidth resource which may perform a dynamic allocation among cells and sectors. It reduces complexity of bandwidth resource allocation in a certain extent, but is still complex for allocation of dynamic bandwidth resource.
U.S. patent application No. 2006/0109865 disclosed a scheme of spectrum bandwidth resource allocation in sectored cells, and disclosed two methods for resolving load equalization in cells.
The first method for load equalization is to inter-borrow bandwidth resource among different sub-sectors in one and the same cell. It doesn't take the interference on adjacent cells into account. Additionally, it may borrow bandwidth from adjacent sub-sector located in a cell different from the current cell. In the second method for load equalization, by changing widths of antenna beams in different sub-sectors, small beams are used in a sub-sector with a heavy load, and large beams are used in a sub-sector with a light load, so as to achieve the load equalization.
In the above technical schemes, when borrowing bandwidth from another sub-sector in one and the same cell, it neither takes the interference on adjacent cells into account, nor takes the situation of bandwidth resource multiplex from adjacent sub-sectors located in a cell different from the current cell into account.